1. Field of the Invention
The present invention relates generally to recycling of cathode-ray tubes (xe2x80x9cCRTsxe2x80x9d), and more particularly, to an apparatus and method for ensuring that the CRT neck is centered and not tilted after the CRT neck is attached to a recycled funnel.
2. Description of the Related Art
In recent years, there has been an increased demand for recycling of natural resources and prevention of environmental destruction. To meet this demand, studies and efforts have been made to reuse CRTs of used television sets and computer monitors.
A CRT, used as an image receiver incorporated in a television set, computer monitor, and the like, is a glass structure composed of a panel portion (also called a face portion) and a funnel portion (also called a panel skirt portion). The panel portion is made from a substantially transparent glass material for improving light transmittance, and the funnel portion is made from a glass material in which lead is mixed for preventing leakage of X-rays caused by collision of electron beams accelerated at a high voltage with a substance. The funnel portion and the panel portion are welded in a shield fashion to each other with frit glass (solder glass) into a tube shape.
An electron gun, a deflection yoke and the like are mounted on the external rear side of a CRT, and a shadow mask (or aperture grill) is provided in the CRT. A fluorescent screen provided on the inner surface side of the panel portion is normally coated with phosphors of three colors (red, green and blue).
Methods of recycling CRTs have been disclosed, for example, in U.S. Pat. Nos. 5,752,868 and 6,089,937. In these known methods, the CRTs are separated into a panel portion and a funnel portion, and the separate components are cleaned, inspected and recycled to make another CRT.
Part of the recycling process is to remove the electron gun, cut off the CRT neck, and re-attach a new CRT neck. When attaching the CRT neck to a recycled funnel, it is very important to ensure that the neck is centered and not tilted. An off center or tilted neck misaligns the electron gun that is inserted and causes a defective CRT.
CRT glass manufacturers use a 3-point system that takes various measurements around the neck in relation to the center of the funnel. Formulas are then applied to account for the thickness of the neck glass. However, in recycling, a quick and easy method was needed to accurately determine whether the new re-necked CRTs had the necks properly centered, aligned and not tilted.
It is an object of the present invention to provide an apparatus and method for ensuring that the CRT neck is centered and not tilted when the CRT neck is attached to a recycled funnel.
It is a further object of the present invention to provide an apparatus for measuring the alignment and tilt of CRT necks which is economical to manufacture, efficient in use, capable of a long operating life, and particularly well adapted for use in inspecting the alignment and tilt of CRT necks attached to recycled funnels.
According to the present invention, an apparatus and method are provided for measuring the alignment and tilt of CRT necks attached to recycled CRT funnel portions to determine whether the CRT necks are within acceptable tolerances. The apparatus includes a support structure having a first surface adapted to engage and support a seal edge of the CRT funnel portion, and a plurality of stopper surfaces extending from the support structure to engage the existing alignment stoppers molded on the CRT funnel portion. First and second distance measuring dial gauges engage lower and upper points, respectively, on a first side of the CRT neck being measured. Third and fourth distance measuring dial gauges engage lower and upper points, respectively, on a second side of the CRT neck. The alignment of the CRT neck is measured by taking readings at the lower points on each of the first and second sides of the CRT neck. The tilt of the CRT neck is measured by comparing the readings from the lower and upper points on each of the first and second sides of the CRT neck. The support structure has a plurality of alignment stoppers arranged to accommodate different sizes of CRT funnel portions.
According to a broad aspect of the present invention, an apparatus for measuring alignment and tilt of CRT necks attached to recycled CRT funnel portions is provided, comprising: a support structure having a first surface adapted to engage and support a seal edge of a CRT funnel portion; at least two stopper surfaces extending from the support structure and adapted to engage respective alignment stoppers molded on the CRT funnel portion to position the CRT funnel portion on the support structure; first and second distance measuring gauges mounted to the support structure, each of the first and second gauges having respective engagement portions adapted to engage the outer surface of a CRT neck being measured, the engagement portions of the first and second gauges being positioned on a first side of the CRT neck and facing the axial center line thereof with the first gauge being positioned below the second gauge; and third and fourth distance measuring gauges mounted to the support structure, each of the third and fourth gauges having respective engagement portions adapted to engage the outer surface of the CRT neck being measured, the engagement portions of the third and fourth gauges being positioned on a second side of the CRT neck and facing the axial center line thereof with the third gauge being positioned below the fourth gauge.
According to another broad aspect of the present invention, an apparatus for measuring alignment and tilt of a cylindrical member attached to a funnel-shaped member is provided, comprising: a support structure having a first surface adapted to engage and support the funnel-shaped member; at least two stopper surfaces connected to the support structure for engaging corresponding surfaces of the funnel-shaped member to position the funnel-shaped member on the support structure; first and second distance measuring gauges mounted to the support structure, each of the first and second gauges having respective engagement portions adapted to engage the outer surface of the cylindrical member being measured, the engagement portions of the first and second gauges being positioned on a first side of the cylindrical member and facing the axial center line thereof with the first gauge being positioned below the second gauge; and third and fourth distance measuring gauges mounted to the support structure, each of the third and fourth gauges having respective engagement portions adapted to engage the outer surface of the cylindrical member being measured, the engagement portions of the third and fourth gauges being positioned on a second side of the cylindrical member and facing the axial center line thereof with the third gauge being positioned below the fourth gauge.
According to another broad aspect of the present invention, a method of measuring alignment and tilt of CRT necks attached to recycled CRT funnel portions is provided, comprising the steps of: providing a first CRT funnel portion having a glass seal edge and first, second and third alignment stoppers molded on the glass seal edge, and a CRT neck attached to the first CRT funnel portion; providing a support structure having a support surface, a first set of alignment surfaces, and four distance measuring gauges; placing the first CRT funnel portion on the support structure with the seal edge on the support surface and the first, second and third alignment stoppers engaged with the first set of alignment surfaces, respectively; measuring an alignment of the CRT neck relative to the seal edge using the distance measuring gauges; and measuring a tilt of the CRT neck relative to the seal edge using the distance measuring gauges.
Numerous other objects of the present invention will be apparent to those skilled in this art from the following description wherein there is shown and described an embodiment of the present invention, simply by way of illustration of one of the modes best suited to carry out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various obvious aspects without departing from the invention. Accordingly, the drawings and description should be regarded as illustrative in nature and not restrictive.